US Bridges

Coyan Rd. over Potholes East Canal

FairPosted for load

Franklin County, Washington · 1.15 E JCT SR 17 · Structure no. 079760000000000

Built
1957
68 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
47 ft
2 main spans
Daily traffic
226
2020 count
Owner
County
County Highway Agency

About this bridge

Coyan Rd. over Potholes East Canal is a wood or timber stringer/multi-beam or girder carrying Coyan Rd. over Potholes East Canal in Franklin County, Washington. It was built in 1957, so it is 68 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.

It carries about 226 vehicles a day, roughly 52% of them trucks, projected to reach 340 by 2040. The structure is 47 ft (14.3 m) long and 25 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesCoyan Rd.
CrossesPotholes East Canal
Location1.15 E JCT SR 17
RouteCounty Highway 2000
CountyFranklin County
StateWashington
Coordinates46.72192, -119.00182
Functional classRural Minor Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2023
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating34 US tons
Inventory rating23.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans2
Design loadH 15
Structure length47 ft (14.3 m)
Longest span23 ft (7 m)
Deck width25 ft (7.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic226 (2020)
Projected traffic340 by 2040
Trucks52%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2.1 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Coyan Rd. over Potholes East Canal built?

It was built in 1957, making it 68 years old in 2025.

What condition is Coyan Rd. over Potholes East Canal in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in November 2023.

How much traffic does Coyan Rd. over Potholes East Canal carry?

About 226 vehicles per day (2020 count), of which roughly 52% are trucks.

How long is Coyan Rd. over Potholes East Canal?

The structure is 47 ft (14.3 m) long with a longest span of 23 ft (7 m) and a deck 25 ft wide.

Who owns Coyan Rd. over Potholes East Canal?

It is owned by the County Highway Agency.